Counterexample Guided Inductive Optimization Applied to Mobile Robots Path Planning (Extended Version)

We describe and evaluate a novel optimization-based off-line path planning algorithm for mobile robots based on the Counterexample-Guided Inductive Optimization (CEGIO) technique. CEGIO iteratively employs counterexamples generated from Boolean Satisfiability (SAT) and Satisfiability Modulo Theories (SMT) solvers, in order to guide the optimization process and to ensure global optimization. This paper marks the first application of CEGIO for planning mobile robot path. In particular, CEGIO has been successfully applied to obtain optimal two-dimensional paths for autonomous mobile robots using off-the-shelf SAT and SMT solvers.Comment: 7 pages, 14rd Latin American Robotics Symposium (LARS'2017

Improvement of bagasse fiber–cement composites by addition of bacterial nanocellulose: an inverse gas chromatography study

The design of green fiber-reinforced nanocomposites with enhanced properties and dura bility has attracted attention from scientists. The present study aims to investigate the potential of bacterial nanocellulose (BNC) as a green additive for fiber–cement composites. Inverse gas chromatography (IGC) was used to evaluate the influence of incorpo ration of BNC as powder or gel, or coated onto the bagasse fibers, on the fiber–cement composite (FCC) surface. The results indicated that BNC incorporation made the FCC surface more reactive, increasing the dispersive component of the surface energy. The most relevant effects were found for BNC incorporation as gel or coated on the fibers. Incorporation of BNC as gel resulted in a predominantly organic FCC surface with substantial decreased surface basicity (Ka/Kb ratio from 2.88 to 5.75). IGC also showed that FCC with BNC incorporated as gel was more susceptible to hydration. However, BNC coated on fibers prevented fiber mineralization, increasing the inorganic materi als at the surface, which caused an increase in the surface basicity (Ka/Kb ratio decrease to 2.00). These promising results could contribute to development of a new generation of green hybrid composites. The IGC technique enabled understanding of the physicochem ical changes that occur on deliberate introduction of nanosized bacterial cellulose into fiber–cement composites.info:eu-repo/semantics/publishedVersio

The Beta Generalized Exponential Distribution

We introduce the beta generalized exponential distribution that includes the beta exponential and generalized exponential distributions as special cases. We provide a comprehensive mathematical treatment of this distribution. We derive the moment generating function and the $r$th moment thus generalizing some results in the literature. Expressions for the density, moment generating function and $r$th moment of the order statistics also are obtained. We discuss estimation of the parameters by maximum likelihood and provide the information matrix. We observe in one application to real data set that this model is quite flexible and can be used quite effectively in analyzing positive data in place of the beta exponential and generalized exponential distributions

Opto-mechanical Response Of A Suspended-slab-core Optical Fiber

In this paper we report the numerical evaluation of the opto-mechanical response of a microstructured optical fiber design when submitted to hydrostatic pressure. The fiber was built in silica and is composed of two large holes surrounding a wide thin flat region (suspended-slab-core) that is able to support optical propagating modes. A full-vector finite element program was used to the stress-optical analysis. The opto-mechanical sensitivity of such fiber was evaluated under two schemes of applied hydrostatic pressure. © American Institute of Physics.1055141144Bjarklev, A., Broeng, J., Bjarklev, A.S., (2003) Photonic Crystal Fibres, , Boston, Kluwer Academic PublishersJoly, N.Y., Birks, T.A., Yulin, A., Knight, J.C., St. Russel, P.J., (2005) Optics Letters, 30 (18), pp. 2469-2471Szpulak, M., Martynkien, T., Urbanczyk, W., (2004) Applied Optics, 43 (24), pp. 4739-4744Schreiber, T., Schultz, O., Schmidt, O., Röser, F., Limpert, J., Tünnermann, A., (2005) Optics Express, 13 (10), pp. 3637-3646MacPherson, W.N., Rigg, E.J., Jones, J.D.C., Kumar, V.V.R.K., Knight, J.C., St, P., Russel, J., (2005) IEEE J. Lightwave Technol, 23 (3), pp. 1227-123

Bentonite from Porto Santo Island, Madeira Archipelago: surface properties studied by inverse gas chromatography

The present paper shows the importance of Inverse Gas Chromatography (IGC) for the determination of the surface properties of bentonites. These properties are dispersive surface energy, acid-base properties, surface heterogeneity, sorption isotherms, BET surface areas and heat of sorption, using different probe molecules. IGC can contribute to the interpretation, prediction and optimization of the studied materials’ properties. The paper focuses on two distinctive bentonite samples from Porto Santo Island, Madeira archipelago. In view of their potential value, achieved through their incorporation in products for dermopharmacy and dermocosmetics, particle size and particle surface properties are of fundamental importance.info:eu-repo/semantics/publishedVersio

Numerical And Experimental Studies For A High Pressure Photonic Crystal Fiber Based Sensor

We report a study of using photonic crystal fibers (PCFs) for high pressure applications. An opto-mechanical analysis was realized in regular PCFs and suspended-core microstructured optical fibers for different fiber geometrical parameters. It was found that the pressure sensitivity is highly dependent on the fiber structure. It was also experimentally shown that even small core PCFs with high air filling fraction can deal with pressures as high as 500 bar (7350 psi) without any noticeable problem. © American Institute of Physics.1055133136de Matos, C.J.S., (2008) CLEO conferenceR.E.P. de Oliveira, submitted to WSOF2008 AIP Proceedings (2008)Cordeiro, C.M.B., (2007) Optics Letters, 32, pp. 3324-3326Szpulak, M., Martynkien, T., Urbanczyk, W., (2004) Appl. Optics, 43, pp. 4739-4744MacPherson, W.N., (2005) Journal Light, 23, pp. 1227-1231. , TechnZhou, J., (2006) OFC'06, WI2Kosolapov, A.F., (2006) Inorganic Materials, 43, pp. 310-31